Galaxy lensing, also known as gravitational lensing, is a phenomenon in which the light from distant galaxies is bent and distorted by the gravitational pull of foreground galaxies or clusters of galaxies. This distortion can create visual effects such as arc-shaped images of background galaxies, multiple images of the same galaxy, or even the appearance of a complete ring of light known as an Einstein ring. Studying galaxy lensing can provide valuable information about the distribution of mass in the universe, as well as the properties of dark matter, which is thought to be a significant contributor to the gravitational lensing effect. By analyzing the distortion of light caused by gravitational lensing, astronomers can infer the mass of the lensing object and gain insights into the overall structure of the cosmos. Overall, galaxy lensing research plays a crucial role in our understanding of cosmology, galaxy formation, and the nature of dark matter in the universe.